Balancing system for a sailing boat

ABSTRACT

A system for maintaining the hull of a sailing boat in a steady position substantially independent of wind pressures on the sail, comprising a pivoted mast and wires connecting the mast with a weight in the boat hull via a transmission device. Transverse pivoting movement of the mast causes lateral displacement of the weight thereby maintaining the hull in a stable condition.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to a balancing system for a sailingboat comprising a mast tiltable laterally about the mast foot.

2. Description of the Related Art

Numerous sailing boat designs have been suggested with the abovementioned features, comprising a transversally pivotably mounted mastthereby utilizing forces transmitted from the wind forces on the sailcausing the transversal mast movement in relation to the hull toangularly rotate the keel or displacing weights transversally in thehull, with the purpose such as to prevent capsizing or maintaining thehull in a substantially stable position. Sailing boats of theaforementioned art are known from e.g. U.S. Pat. Nos. 559,983, 830,720,3,099,976 and U.S. Pat. No. 3,985,106.

From SE 456 237 is furthermore known a sailing boat in which wiresattached to the mast act on hydraulic cylinders from which a hydraulicfluid of a hydraulic system is transferred to hydraulic devices adaptedto transversally displace balancing weights inside the hull, preferablynear the hull bottom. The hydraulic system may be set to a desiredtransmission ratio between the mast wire movement and the weight wiremovement, e.g. a certain heeling angle of the mast is causing a desiredlateral displacement of the balancing weight.

Prior art sailing boat balancing systems, however, are complex, partlycomprising a large number of space consuming means, requiring hydraulicsystems for the transmission of the mast movement to the weight devicesand also for effecting the transversal displacement of the balancingweights.

SUMMARY OF THE INVENTION

The present invention is related to a balancing system designated tomaintain the hull of a sailing boat in a desired steady position, suchas horizontally, essentially independently of wind forces exerted on thesail, thereby utilizing a transversal tilting of the mast in relation tothe hull of the sailboat to transversally displace a weight inside thehull by means of wires connected to the mast and the weight via at leastone transmission device.

For this purpose arrangements are made for displacement of a balancingweight in the transverse direction by means of direct actuation on theweight by wires connected with the mast, in dependence of the heelingangle of the mast, in addition to which, the ratio between the lateraldisplacement of the balancing weight and the heeling angle of the mastmay be set to a desired value. Furthermore it is required to maintainthe interior of the hull free of equipment connected to the balancingsystem, thereby to be utilized by the sailing boat user.

With the balancing system according to the present invention the abovementioned advantages are achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawing FIG. 1 discloses a vertical longitudinal center sectionof a sailing boat comprising one embodiment of the balancing system ofthe present invention, FIG. 2 discloses a cross section along II--II inFIG. 1, FIG. 3 discloses a ground view of the embodiment disclosed inFIGS. 1 and 2 of the inventive balancing system, FIG. 4 discloses crosssection corresponding to FIG. 2 of a second embodiment of the presentinvention, FIG. 5 discloses a partial ground view corresponding to FIG.3 of the second embodiment of the present invention, FIG. 6 discloses apartial longitudinal section corresponding to FIG. 1 of the secondembodiment, FIG. 7 discloses a halc cross section corresponding to FIG.2 of a third embodiment of the present invention, FIG. 8 discloses apartial longitudinal section corresponding to FIG. 1 of the thirdembodiment and FIG. 9 discloses a ground partial view corresponding toFIG. 3, of the third embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The mast 1 of the sailing boat is supported in a mast bearing 15substantially at the deck level, allowing lateral tilting movements ofthe mast. Wires 2 and 3 are connected to an upper portion of the mast,preferably to a transverse stay on the mast. The wires 2 and 3 areguided downwards to guide blocks 10 at deck level and through the deckto guide blocks 9 in the interior of the hull. Between the interiorblocks 9 and the transverse stays tensioning devices, such as 11 arearranged, maintaining a substantially constant prestress in the wires,thereby absorbing slack.

A balancing weight 5 is supported for transverse movement inside thehull, preferably near the bottom. The weight 5 is supported by atransversal rail 16 substantially following the cross section shape ofthe hull, by means of not shown rollers. Additional Guiding rollers 12are positioned at each weight end travelling in correspondingly shapedtransverse rails 4. Preferably, the Guiding rails 4 are U-shaped railshaving the rollers 12 positioned between the flanges. Rail 16 and rails4 are curved transversely in such a manner that the weight 5 may bedisplaced in both transversal directions in the hull with minimumfriction. An appropriately curved shape of rails 16 and 4 is chosen incorrespondence with the desired balancing effect in relation to the windpower and transmission ratio between the pivotal movement of the mastand the desired transversal movement of the weight. Accordingly, and asshown in the figures, weight 5 is slidingly mounted on the bottom of thehull, and is movable transversely across the bottom thereof.

In the embodiment disclosed in FIGS. 1-3 wires 2 and 3 extend furthertowards the middle of the hull to a drive arm 6 to which both wires areadjustably and detachably attached, the attachment point on the arm, ifdesired, thereby being adjustable, thereby adjusting the distancebetween the arm attachment point 8 and the weight attachment point. Thedriver arm 6 is pivotally attached to the balancing weight 5 to allowthe transversal movement of the weight.

The driver arm 6 is pivotally mounted to an arm holder member 7 allowingthe arm to pivot about a vertical axis. If desired the arm holder member7 may be adjustably secured to the hull, being displaceable in thelongitudinal direction of the boat as to affect, in combination withsuitable setting of the position of the wire attachment 8 to the arm,adjustment and calibration of the angular movement of the driver arm andthus the transversal movement of the weight in response to a givenheeling angle of the mast 1 in relation to the hull, the end of thedriver arm 6 opposite the arm holder member 7 thereby being pivotallyattached to the balancing weight 5.

In order to dampen the movements of the weight, particularly result fromwave influences on the hull, a hydraulic braking device 13 may besecured to the weight 5. The braking device comprises a geartransmission of which a gear engages a toothed rack attached to the rearrail 4 thereby dampening a transversal weight movement. The brakingeffect of the braking device 13 may be set hydraulically for adaptationto the prevailing conditions.

Wind forces acting on the sail will rotate the mast 1 about its bearing15 as disclosed in FIG. 2, pulling the wire 2 upwards, slackening thewire 3 and allowing it to be pulled downwards thereby rotating the drivearm 6 its vertical axis in the arm holder member 7, thereby displacingthe weight 5 laterally in such a manner that the wind force transmittedvia the wires is counteracted by a corresponding oppositely directedresultant force from the weight 5. The displacement of the weight 5causes the driver arm 6 to move longitudinally inside the arm holdermember 7 thereby to establish a longer driver arm 6 allowing the weightto move strictly transversally in the hull. The weight 5 is displaced onrails 16 and guided by means of the rollers 12 at minor friction forcesdue to the precise guidance of the weight 5 by the guide rollers 12 inrails 4 as well as the guidance on the rail 16.

The object of the invention is to maintain the hull in the desiredposition, e.g. in a horizontal position, essentially independently ofthe wind forces on the sail and thus on the mast 1.

When the wire 2 is made taut as a consequence of the mast movements theleeward wire 3 will slacken but this slackening will immediately beabsorbed by the tensioning device 11. The tensioning device 11 ensuresthat the wire constantly is maintained prestressed or biased.

The ratio of the mast heeling angle and consequently the prolongation ofthe wire 2 to the movement of the weight 5 in relation to the centerplane of the hull, may be adjusted by changing the position of theattachment of the wires 2 and 3 to the driver arm 6 along the lengthwisedirection of the arm in such a manner that the distance from saidattachment 8 to the pivot axis of the arm holder member 7 may bealtered. The extent of the angular displacement of the driver arm as aresult of an angular displacement of the mast 1 therefor is depending onthe angle position of the driver arm from the hull center line. Thetensioning devices 11 automatically adjust the degree of wire tightness.

A further possibility of adjustment of or changing the relationshipbetween the mast tilting angle and the movement of the weight may beachieved by displacing the arm holder member 7 in the longitudinaldirection of the hull such that the center of the turning movement ofthe drive arm 6 is altered.

The various possibilities of adjustment, such as the attachment 8 of thewires to the driver arm and the positions of the arm holder member 7,allow adaptation of the system to the desires and needs of the sailorwith regard to the specific hull design and expected wind and seaconditions.

Additionally, a further possibility of adjustment exists on account ofthe damping effect exerted by the hydraulic dampening motor unit 13 onthe movements of the weight 5, which motor is provided particularly witha view to dampen weight motions caused by waves.

FIG. 4 through 6 illustrate a modification of the balancing systemaccording to the present invention. As in the previously describedembodiment, the weight 5 is supported on rail 16 and guided in rails 4by suitable rollers.

Transfer of the mast tilting movements for effecting lateraldisplacement of the weight 5 is however in a second embodiment effectedby a transmission device comprising at least one transmission block 17,which may even be adjustable. The transmission ratio of the block 17normally will be chosen for a certain sailing boat by the diameter ofthe wheel for the incoming wire 2 from the mast in relation to thediameter of the outgoing wheel for the wire to the weight. As in theprevious described embodiment the wires 2 and 3 are biased by tensioningdevices 11, one of which being disclosed in FIG. 4. Also this embodimentof the invention obviously may be equipped with a hydraulic dampeningmotor, not illustrated in the drawings.

FIGS. 4-6 disclose a second embodiment comprising two transmissionblocks 17 arranged one on each side of the center axis, preferablyunderneath the guiding blocks 10. FIGS. 7-9 disclose a third embodimentcomprising only one transmission block 17 being arranged at a level inthe hull substantially corresponding with the weight level, therebyproviding a hull the interior of which not being occupied by meansconnected with the balancing system.

The transmission block or blocks 17 may consist simply of two wheelshaving different radii and having a common shaft to which both wheelsare rigidly secured. The transmission blocks also may be of a typecomprising a series of wheels having different radii, wheels of conicalperiphery comprising helical grooves therein or any form of infinitelyvariable pulley mechanism thereby to provide a transmission block typewith a variable transmission ratio.

From the two transmission blocks 17 of the second embodiment or thesingle block 17 of the third embodiment the left and right wires areguided via pulleys to be connected preferably to the middle of theweight 5, above the rail 16.

The third embodiment comprises, as disclosed in FIG. 7, tensioningdevices 11 included in the guide blocks 10.

We claim:
 1. A balancing system for a sailing boat, said sailing boathaving a hull, said hull having a first and a second side, comprising:amast pivotally attached to said sailing boat and tiltable transverselywith respect to said hull; a weight within said hull, said weight beingslidingly mounted on the bottom of said hull and movable transverselyacross the bottom thereof; a first wire and a second wire, each of saidwires having a first and a second end, said first end of each of saidwires being attached to said mast; a first guide block and a secondguide block, said first and second guide blocks being on said first andsecond sides of said hull, respectively, said first and second wirespassing around said first and second guide blocks, respectively, andinto said hull; and means within said hull for transmitting a transversetilt of said mast to said weight, said second ends of said wires beingattached to said means, said means being operably connected to saidweight, so that a transverse tilt of said mast in one direction maycause a transverse movement of said weight in the opposite direction,whereby said sailing boat may be maintained in a stable condition,wherein said transmitting means comprises a first and a secondtransmission block on said first and second sides of said hull,respectively, and a weight wire, each of said first and secondtransmission blocks having a first and a second wheel, said second endsof said first and second wires being attached to said first wheels ofsaid first and second transmission blocks, respectively; and said weightwire having a first end, a middle and a second end, said first end ofsaid weight wire being attached to said second wheel of said firsttransmission block, said middle of said weight wire being attached tosaid weight, and said second end of said weight wire being attached tosaid second wheel of said second transmission block.
 2. A balancingsystem as claimed in claim 1 further comprising a first and a secondtensioning device for said first and second wires, respectively, saidtensioning devices being constantly biased to eliminate slack from saidfirst and second wires.
 3. A balancing system as claimed in claim 1further comprising a tensioning device for said weight wire, saidtensioning device being constantly biased to eliminate slack from saidweight wire.
 4. A balancing system as claimed in claim 1 wherein saidfirst and second wheels of said first and second transmission blockshave diameters different from one another.
 5. A balancing system for asailing boat, said sailing boat having a hull, said hull having a firstand a second side, comprising:a mast pivotally attached to said sailingboat and tiltable transversely with respect to said hull; a weightwithin said hull, said weight being slidingly mounted on the bottom ofsaid hull and movable transversely across the bottom thereof; a firstwire and a second wire, each of said wires having a first and a secondend, said first end of each of said wires being attached to said mast; afirst guide block and a second guide block, said first and second guideblocks being on said first and second sides of said hull, respectively,said first and second wires passing around said first and second guideblocks, respectively, and into said hull; and means within said hull fortransmitting a transverse tilt of said mast to said weight, said secondends of said wires being attached to said means, said means beingoperably connected to said weight, so that a transverse tilt of saidmast in one direction may cause a transverse movement of said weight inthe opposite direction, whereby said sailing boat may be maintained in astable condition, wherein said transmitting means comprises atransmission block and a weight wire, said transmission block having afirst and a second wheel, said second ends of said first and secondwires being attached to said first wheel of said transmission block; andsaid weight wire having a first end, a middle and a second end, saidfirst and second ends of said weight wire being attached to said secondwheel of said transmission block, and said middle of said weight wirebeing attached to said weight.
 6. A balancing system as claimed in claim5 further comprising a tensioning device for said weight wire, saidtensioning device being constantly biased to eliminate slack from saidweight wire.
 7. A balancing system as claimed in claim 5 wherein saidtransmission block is mounted on said bottom of said hull adjacent tosaid weight.
 8. A balancing system as claimed in claim 5 wherein saidfirst and second wheel of said transmission block have diametersdifferent from one another.
 9. A balancing system as claimed in claim 5further comprising a first and a second tensioning device for said firstand second wires, respectively, said tensioning devices being constantlybiased to eliminate slack from said first and second wires.